Chelating agents and method

Abstract

A simple method for making EDTA, ED3A or DTPA analogs from amide derivatives of alpha amino acids is disclosed. These EDTA, ED3A or DTPA analogs are useful chelating agents, and preferably are useful as bifunctional chelating agents which may be attached to biological molecules and which form physiologically stable chelates with a variety of metal ions.

We claim: 
     
       1. An optically active and substantially optically pure chelating agent comprising: an EDTA, ED3A, or DTPA analog having a central ethylene moiety, said ethylene moiety being substituted at a one carbon thereof by an R moiety substituent, said R moiety substituent being an amino acid side group including a methylene group through which said amino acid side group is bonded, and selected from the group consisting of ##STR10##  said one carbon defining an L or D stereochemical configuration for said EDTA, ED3A or said DTPA analog.   
     
     
       2. A chelating agent having the structure ##STR11## wherein ##STR12## 
     
     
       3. An optically active and substantially optically pure chelating agent having the structure ##STR13## wherein R 1  is --CH 2  COOH, --CH 2  CH 2  OH, or --CH 2  CH 2  N(CH 2  COOH) 2  and R is an alpha amino acid side group selected from the group consisting of leucine, phenylalanine, tryptophan, methionine, serine, cysteine, tyrosine, methyl tyrosine, methyl tryptophan, and p-nitrophenylalanine. 
     
     
       4. An optically active and substantially optically pure chelating agent having the structure ##STR14## wherein R 1  is --CH 2  CO 2  H, CH 2  CH 2  OH, or --CH 2  CH 2  N(CH 2  COOH) 2 , and R 2  is selected from the group consisting of --OH, NH 2 , and --NO 2 .